Abstract

This 12-month prospective longitudinal study used acoustic analysis to identify phonational gaps in the vocal range of adolescent boys undergoing voice change and to investigate the relationship between the appearance of phonational gaps, weight gain, and changes in speaking fundamental frequency (SF 0). Eighteen pubescent boys were recorded producing three descending and three ascending glides over their physiological voice range using the vowel “ah.” Recordings were digitized over the range 0–16 kHz and then analyzed to determine both the frequency range and appearance and frequency characteristics of the phonational gaps. Data were plotted against changes in weight and SF 0 both as an indicator of pubertal development and to test the hypothesis that changes in weight and SF 0 were related to the appearance of phonational gaps. Results indicated that minimum F 0 decreased significantly over the time period and phonational gaps increased significantly, but there were no significant changes in maximum F 0 or range. Individual data indicated the initial appearance of a lower-frequency gap followed by a higher-frequency gap before the long-term establishment of a midrange gap. At time 5, all boys in the weight range 42.7–44.9 kg had either low- or high-range gaps. The SF 0 for this group varied from 117 to 216 Hz. All boys heavier than 54.8 kg had highly variable phonational gaps. SF 0 range for this group was 99.5–151 Hz. Transitory low- then high-frequency phonational gaps appeared before the establishment of a midrange phonational gap. In this study, these phonational gaps were associated with certain weight ranges and rapid weight gain, with changes to boys' speaking voices, and with loss of ability to use the mid- and falsetto vocal range.